Phân tích thành nhân tử: A, 15x ² +7x-2 B) a ²-5a-14 04/07/2021 Bởi Raelynn Phân tích thành nhân tử: A, 15x ² +7x-2 B) a ²-5a-14
Đáp án: `a) 15x^2+7x-2=15x^2-3x+10x-2` `=3x(5x-1)+2(5x-1)` `=(5x-1)(3x+2)` `b) a^2-5a-14=a^2-7a+2a-14` `=a(a-7)+2(a-7)` `=(a-7)(a+2)` Bình luận
`a, 15x^2+7x-2` `=15x^2-3x+10x-2` `=3x(5x-1)+2(5x-1)` `=(5x-1)(3x+2)` `b, a^2-5a-14` `=a^2-7a+2a-14` `=a(a-7)+2(a-7)` `=(a+2)(a-7)` Bình luận
Đáp án:
`a) 15x^2+7x-2=15x^2-3x+10x-2`
`=3x(5x-1)+2(5x-1)`
`=(5x-1)(3x+2)`
`b) a^2-5a-14=a^2-7a+2a-14`
`=a(a-7)+2(a-7)`
`=(a-7)(a+2)`
`a, 15x^2+7x-2`
`=15x^2-3x+10x-2`
`=3x(5x-1)+2(5x-1)`
`=(5x-1)(3x+2)`
`b, a^2-5a-14`
`=a^2-7a+2a-14`
`=a(a-7)+2(a-7)`
`=(a+2)(a-7)`